Earthquake Engineering (3160621) MCQs

MCQs of Fundamentals of Earthquake Vibrations of buildings

Showing 11 to 20 out of 53 Questions
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11.

Which among the following is the fundamental equation of S.H.M.?

(a)

x + (k / m) x =0
(b)

x + ω2x = 0
(c)

x + (k / m)2 x =0
(d)

x2 + ωx2 = 0
Answer:

Option (b)

12.

A stretched string of a guitar when operated is subjected to

(a)

Free vibrations
(b)

Forced torsional vibrations
(c)

Forced vibrations
(d)

Damped vibrations
Answer:

Option (c)

13.

Determine natural frequency of a system, which has equivalent spring stiffness of 30000 N/m and mass of 20 kg?

(a)

12.32 Hz
(b)

4.10 Hz
(c)

6.16 Hz
(d)

None of the above
Answer:

Option (c)

14.

Calculate natural frequency of damped vibration, if damping factor is 0.52 and natural frequency of the system is 30 rad/sec which consists of machine supported on springs and dashpots.

(a)

25.62 rad/sec
(b)

20.78 rad/sec
(c)

14.4 rad/sec
(d)

15.33 rad/sec
Answer:

Option (a)

15.

Calculate logarithmic decrement if damping factor is 0.33.

(a)

1.36
(b)

3.23
(c)

5.16
(d)

2.19
Answer:

Option (d)

16.

In damped free vibrations, which parameters indicate vibrations?

(a)

Natural frequency
(b)

Rate of decay of amplitude
(c)

Both (a) and (b)
(d)

None of the above
Answer:

Option (c)

17.

Which of the following statements is/are true for coulomb damping?

1. Coulomb damping occurs due to friction between two lubricated surfaces.

2. Damping force is opposite to the direction of motion of vibrating body.

3. For smooth surfaces, coefficient of friction depends upon velocity.

4. Damping force depends upon the rubbing velocity between two rubbing surfaces.

 

(a)

Only statement 1
(b)

Statement 2, 3 and statement 4
(c)

Only statement 2
(d)

All the above statements are true
Answer:

Option (c)

18.

What is meant by critical damping coefficient?

(a)

Frequency of damped free vibrations is less than zero.
(b)

The motion is a periodic in nature.
(c)

Both (a) and (b).
(d)

None of the above
Answer:

Option (b)

19.

Calculate coefficient of viscous damper, if the system is critically damped. Consider the following data:

Mass of spring mass damper system = 350 kg

Static deflection = 2 x 10–3 m

Natural frequency of the system = 60 rad/sec

 

(a)

100.5 x 103 N·s/m
(b)

80 x 103 N·s/m
(c)

42 x 103 N·s/m
(d)

None of the above
Answer:

Option (c)

20.

Determine logarithmic decrement, if the amplitude of a vibrating body reduces to 1/6th in two cycles.

(a)

0.223
(b)

0.8958
(c)

0.3890
(d)

None of the above
Answer:

Option (b)

Showing 11 to 20 out of 53 Questions
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